AbstractWe explored a modified, computer-aided monitoring system for continuous, long-term recording of Bivalvia cardiac activity. To estimate the capabilities of this system, we used it to monitor the cardiac activity of a mussel (Mytilus edulis) under predation threat from a starfish (Asterias rubens). In addition, we used a web camera to track the behavioral responses of these animals. Compared to its state during normal feeding activity, the mussel's heart rate showed no significant changes when the mussel was near the starfish. However, when the mussel was attacked by the starfish, its heart rate and contraction power (i.e., amplitude) increased and subsequently decreased down to the absence of any heartbeats within 2.5 hours. The results obtained in this study proved the usefulness of this new system as a stress-monitoring tool.AbstractFor animal embryos that develop externally, the physio-chemical environment can substantially affect offspring viability. In the case of the American horseshoe crab (Limulus polyphemus), sediment conditions along estuarine shorelines influence development rates and embryonic viability. Sandy beach habitats are considered to have optimal conditions for horseshoe crab embryonic development; however, spawning is often observed outside of these optimal habitats, in areas such as salt marshes, where reduced oxygen availability is thought to decrease the viability of eggs laid in these sediments. We excavated horseshoe crab eggs, embryos, and trilobites laid naturally in marsh and beach sediments in South Carolina to compare their development and viability between habitats. We found all developmental stages in both marsh and beach habitats. For two of three sampling areas, trilobites were more likely to be found at beaches than at marshes. Multivariate analyses demonstrate that the prevalence of early and middle developmental stages was similar between habitats but that beaches had a greater proportion of late-stage trilobites than marshes. The lower likelihood of finding trilobites at some marshes may reflect differences in spawning phenology between habitats or reduced rates of embryonic development in marshes compared to beaches, leading to potentially different developmental timelines rather than a true reduction in viability. Nevertheless, the substantial proportions of eggs laid in salt marshes that survive to the trilobite stage indicate that spawning in this habitat could represent a previously underappreciated source of recruitment for horseshoe crab populations that may need to be incorporated into population assessments.AbstractAs coral reefs experience dramatic declines in coral cover throughout the tropics, there is an urgent need to understand the role that non-reef habitats, such as mangroves, play in the ecological niche of corals. Mangrove habitats present a challenge to reef-dwelling corals because they can differ dramatically from adjacent reef habitats with respect to key environmental parameters, such as light. Because variation in light within reef habitats is known to drive intraspecific differences in coral phenotype, we hypothesized that coral species that can exploit both reef and mangrove habitats will exhibit predictable differences in phenotypes between habitats. To investigate how intraspecific variation, driven by either local adaptation or phenotypic plasticity, might enable particular coral species to exploit these two qualitatively different habitat types, we compared the phenotypes of two widespread Caribbean corals, Porites divaricata and Porites astreoides, in mangrove versus lagoon habitats on Turneffe Atoll, Belize. We document significant differences in colony size, color, structural complexity, and corallite morphology between habitats. In every instance, the phenotypic differences between mangrove prop root and lagoon corals exhibited consistent trends in both P. divaricata and P. astreoides. We believe this study is the first to document intraspecific phenotypic diversity in corals occupying mangrove prop root versus lagoonal patch reef habitats. A difference in the capacity to adopt an alternative phenotype that is well suited to the mangrove habitat may explain why some reef coral species can exploit mangroves, while others cannot.This study investigated the effects of particle transfer to the covers of aerosol samplers during transportation of wood dust and welding fume samples. Wood dust samples were collected in a sanding chamber using four sampler types closed-face cassettes (CFC), CFC with Accu-CAP inserts, disposable inhalable samplers (DIS), and Institute of Occupational Medicine (IOM). Welding fumes were collected in a walk-in chamber using the same samplers, with Solu-Sert replacing Accu-CAP. The samples were divided into two groups, with one group transported by air and the other by land. They were returned in the same manner and analyzed gravimetrically for wood dust and chemically for welding fumes. For wood dust, IOM showed a significantly higher percentage of particles transferred to the covers compared with the other samplers regardless of the transportation mode (p? less then ?0.0001; 64% by air and 15% by land), while other samplers showed less than or close to 10% (3.5-12%). When the percentages of particle transfer to the covers were compared between the air and land transportation, both IOM and CFC samples showed differences between modes of transportation, while others did not. For welding fumes, most samples (61% of samples for copper [Cu] and 76% of samples for manganese [Mn]) showed nondetectable amounts of the analyte on the covers. For all samplers, the particle transfer to the covers for both transportation modes ranged from 0.2-33% for Cu and less than 4.5% for Mn. Overall, this study confirms that particle transfer to sampler covers during transport highly depends upon the transportation mode and sampler type for wood dust, whereas particle transfer seems minimal for welding fumes. The findings of this study are based on two materials and limited sample sizes. https://www.selleckchem.com/products/abbv-cls-484.html Further investigation considering different industry types and tasks, particle size ranges, and materials might be necessary. Nevertheless, occupational professionals should account for this transfer when handling and analyzing samples in practice.